1. Field of the Invention
This invention relates to a motor driven adjustable filling assembly for a fluid dispensing apparatus.
2. Description of the Prior Art
U.S. Pat. No. 4,402,461 discloses a liquid-dispensing nozzle having a reciprocating bellows communicating with a fluid inlet arrangement. A driving member is connected to the bellows for reciprocating the bellows and an outlet valve is arranged in the fluid inlet to open and allow the fluid to flow from the bellows during a pressure stroke. An inlet valve is also arranged to open to allow the fluid to flow to the bellows during a suction stroke of the bellows. A second bellows is connected upstream of the inlet valve and the driving member is connected to a section of the fluid inlet between the bellows for reciprocating the section and the inlet valve and, therefore, both of the bellows.
As described in the patent, the driving member is a piston rod and hydraulic or pneumatic ram assembly which acts between a frame member and a bracket of the section. The cylinder of the hydraulic or pneumatic ram is fixed to the frame. A separate ram and piston rod arrangement is provided for each double bellows type fill arrangement. In an initial condition of operation of the device, the valve member 43 would be in the closed position and both of the bellows 30 and 35 would be full of liquid to be fed to the dispensing nozzle 37 and then to a carton C below the nozzle.
The ram 42 displaces the bracket 40 upwards from its rest position. The pressure of the liquid in the bellows 30 on the inlet valve 33 opens the valve against the action of a closing spring 33' and the liquid flows into the bellows 35 as the ducting section 32 moves upwards and compresses the bellows 30. When the ram 42 reaches its upper end position and begins to return downward, the valve 33 will automatically close and the liquid in the bellows 35 is pressed by the ram 42 against a driving part 46. Some of the liquid will pass through gaps 54 and 56; however, the rate of flow through the gaps is not enough to prevent a significant increase of pressure on the driving part 46 so that the ram member 42 moves downward against the action of the spring 48 until the driving part 46 abuts against the lugs 52 and limits any further downward movement of the member 43. Under the pressure of the ram 42, the liquid in the bellows 35 continues to flow through the gaps 54 and 56.
From the foregoing description of operation, it can be appreciated that the driving ram 42 and associated piston 41, of the prior art machine does not act to control the amount of liquid received by the upper bellows 30. Accordingly, the device operates at a disadvantage of not being able to preset the stroke of the piston and ram assembly so as to preselect a desired amount of fluid to be directed to an uppermost ducting or fluid inlet section.